Experimental and molecular dynamics simulation study on antifouling performance of antimicrobial peptide-modified aluminum alloy surfaces

Marine biofouling poses a major challenge to ship navigation and hinders the development of the shipping industry. Urgent action is required to tackle this problem through the implementation of innovative strategies. Antimicrobial peptides have garnered considerable attention due to their outstanding effectiveness, wide range of activity, and eco-friendly characteristics. This study involved grafting the antibacterial peptide andricin 01 (AIGHCLGATL) onto the surface of an aluminum alloy, thereby creating a modified surface with antibacterial properties. In summary, amino groups were introduced onto the surface of aluminum alloys through the silanization process using (3-aminopropyl) triethoxysilane (APTES), and then the peptides were covalently immobilized on the treated surface using glutaraldehyde as a cross-linking agent. The successful modification of the peptide was confirmed by Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis. The antimicrobial peptide-modified aluminum alloy surfaces exhibited significant bactericidal activity, killing 75.3% of Bacillus sp. and 85.5% of Escherichia coli, while achieving antifouling efficiencies of 88.6% and 90.7% against Bacillus sp. and E. coli, respectively. Furthermore, molecular dynamics simulations showed that the inserted of the peptides into the phospholipid membrane caused a change in the local membrane curvature, which eventually led to membrane rupture. These results provide valuable information for the application of antimicrobial peptides in the field of antifouling and the elucidation of antifouling mechanisms.